In this study bronchoalveolar lavage will be performed on normal volunteers and the results will be compared with the data from patient populations. Fiberoptic bronchoscopy, bronchoalveolar lavage and bronchial brushing will be performed according to standardized procedures. The BAL cells will be quantified and a cell differential made. The lab was used for the following: BAL analysis, ELISA, Northern analysis, PCR, RNA isolation, ultracentrifugation, oligonucleotide synthesis, recombinant DNA techniques, DNA sequencing (automated) and use of laminar flow hoods.